Untill they are 18.
Only if an order is already in place.
No.
If the person is a child, ie. under 18 years of age, then yes. If the person is no longer a child, ie 18 and over (which is the legal adult age in Texas, then no.
17-35%
no
There are no applicable laws in any state that says the person receiving the child support must be actually spending the money on the child, so no. However, it could be addressed as an issue of abandonment of the child if the mother is in Texas and the child is in Missouri.
both of them
yes
yes
if a divorced couple decides to get back together, which is great by the way, then whoever was receiving the child support has the oppurtunity to say it's over he doesnt need to pay it anymore. that person would have to go back to court before the judge to change it.
no, 11 years to late.
You sue the person for child support. Just because you pay child support for one child does not mean you can not receive child support for the one you have custody of.